Process of preserving wood.



F chemicals, and has for its object to render then ready for the secondstep of the proc- CHARLES H. CURTIS, ARGOS, INDIANA.

PROCESS OF PRESERVING \VQOD.

N0 Drawing.

Specification of Letters Pritent.

Patented Apr. 2, 191.2.

Application filed April I0, 1911. Serial No. 620,091

To all wlzmn it may concern Be-it known that I, Cuanms H. Cnirris, acitizen of the United States, residing at Argos, in the county ofMarshall and State of Indiana, have invented certain new and usefulInuirovements in Processes for Presin-ring Wood; and T do hereby declarethe Following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to process for treating wood to preserve thelatter by sub jeeting it to a solution composed of certain the. woodstronger and more durable and to give it longer life.

In treating the wood by means of the solution employed, the wood firstsawed or carved into the desired shape or design. The sap and moistureis then driven out either by the h at of the sun or an ordinary drykiln, or the ordinary vacuum pump apparatus may be employed. "lhc woodis ess, which consists of bath in a solution having the followingingredients and made in the following manner: Two parts of an alkali,preferabiy sodium carbonate (N21,,CQ.) are thoroughly mixed with onepart of silica (SiO), pure White sand and ground dry by any ordinaryltllll wh ch 15 capable of grinding.tinely. The nurture is then fused inan ordinary furnace forming a soluble alkali silicate it is then allowedto cool and again ground to a line powder. The mass is then dissolved inwater (lhfi) and chlorin ((ill.) is then added. The solution is thenready to receive the wood to be treated, which should be iunuediatelyplaced therein.

(lhlorin ((ll') will unite with an equal volume of the hydrogen (ll) ofthe "water, l'n-ming llydroehloric acid (llC-l); a sutlicient quantityof chlorin (Ci) being added to l orm one pound of hydrochlmric acid(llCl) for each pound of silica (slog originally employed.

The solution may be injerted into the wood by either the open tanl; orpressure u'u'thods now employmd for such purpo,

When the cells and interccllular symres of the wood are Jilled with thesolution, the wood is placed in the hot sun or subjected to a moderateheat in a dry kiln. The heat completes the union of the chlorin (Cl) andthe hydrogen (ll) in the cells and intercellular spaces of the wood,leaving si.icon (Si) to unite with the two parts oxygen (0,), formingsiliea (S10 which remains in the wood, while h ydrochloric acid (HCl)is, by means of heat, drawn from the. wood, destroying at the same timea small portion of the wood fiber. The wood is again dried out, asdescribed in the first step of the process, and then given a. secondbath in the. solution, as described in the second step. The drying isagain repeated and the wood subjected. to a third bath. The steps of theprocess are repeated in regular order until the natural cells andintercellular spaces and the spaces made by the destruction of a portionof the wood fiber by the hydrochloric acid (IICl) are completely pluggedor filled up with silica (SiO,).

The wood at this stage of treatment is especially suitable for such usesas railroad ties, posts, telegraph and telephone poles, bridge timber,piling, etc., and for shingles and other building material.

Should a completely silicified wood be desired, the wood after beingtreated as above described, is subjected to a bath of sul'l'urie acid (H30 under pressure, \\'lll(5li more readily destroys the wood fiber thandoes the hydrochltn'io acid (H01). It-

is removed from the solution when only a small portion of lhe wood fiberhas been destroyed. It is then put through steps munber one and two,thereby filling the spaces normally occupied by the destroyed fiber withthe silica (SiO as the cells, inlet-cellular and other spaces werefilled in the first steps of the process. If desired, the treatment mayhe continued, using the sulfuric arid (l-LSOJ bath until the wood iscompletely petrified.

During the above described preserving process all living organisms andfungi are killed and the finished product cannot be harmed by such wooddestroyers.

The more porous and so called inferior woods otter treatment by thisprocess are rendered just as desirable as, if not more dosirable thanthe high grade woods. Therefore. this process may be employed forpreserving wood of all grades. And as Ineelumirul abrasion is the chiefdestructive agent oi a wood treated by this process, all

wood. so tr ated will be of great; Value for all purposes for which Woodis en'iployed. Further, as the Wood so preserved will have a practicallyendless lite the result will be an enormous annual saving of the rapidlyv diminishing tiinber reserves.

Whati claim is: 1. The process of prising preparing a gether sodiumcarbonate solution by fusing to and finely ground v silica, cooling' andpulverizing the frit, dis

solving the same in Water, treating said solution with chlorin gas;drying the Wood by heat immersing the dried Wood in said solution,removing the wood from the bath and tying the same, and thereafterrepeat ing t e steps of immersing the Wood in the n and drying thesameuntil the Wood is 1inregnated to the desired degree.

2 he "rocess of reservin WOOd oompt-ising preparing a solutionoy fusingtogether sodium carbonate and finely ground silica, cooling andpulverizing the frit, dissolving the same in Water, treating saidsolution with chlorin gas; drying the Wood by heat; immersing the dried'WOOCt in said solution, removing the Wood from the bath and dryingpreserving Wood, com-- the same, and thereafter repeating the wood byheating. 3. The process of preserving Wood, com

the steps of immersing the Wood in the solution and drying the sameuntil the Wood 15 impregnated to the desired degree, thereafterimmersing said Wood in a bath of di lute sulfuric acid under pressure,to render the slhca insoluble, and then a g'am drying thereafterrepeating the steps ofimmersing the Wood in the solution and drying thesame until the Wood is desired degree In testimony whereof I have signedmy name to this specification in the presence of two subscribingWitnesses.

CHARLES H. CURTXS.

impregnated to the vVitnesses:

Cimmyns W. WoR'rMAN, FRANK M. PICKERL

